Detachable fin for boats



Oct. 8, 1929. w. s. DUP UIS DET ACHABLE FIN FOR BOATS Filed July 21, 1928 Inventor WSiJu Ju is Attormgy rammed Oct. 8, 1929 UNHTED STAT.)

PATENT orrics WILLIAM S. DUPUIS, OF PLTZ'IYIOIJTH, IHIASSACHUSE'ETS, ASSIG-NOR OF OIN'EJIALF TO A. PERRY RICHARDS, OF EFLYMOU'EH, TIZASSAGHUSETTS DETACHAELE FIN FOR BOATS Application filed July 521, 1928. Serial No. 294,3?0.

The present invention relates to a fin for boats and has for its prime object to provide a structure which may be easily and quickly attached to and detached from the boat so that the boat may be transported without danger of breaking the fin.

A still further very important object or the invention resides in the provision of a quick detachable fin which is simple in its construction, inexpensive to manufacture, thoroughly eificient and reliable in use, easy to manipulate, and otherwise well adapted to the purpose for which it is designed.

l fith the above and numerous other objects in view as will appear as the description proceeds, the invention resides in certain novel features of construction, and in the combination and arrangement of parts as will be hereinafter more fully described and claimed.

In the drawing:

l igure 1 is a fragmentary side elevation of a lower portion of a boat showing my detachable fin mounted therein, portions being shown in section, and

Figure 2 is a vertical transverse section taken substantially on the line 22 of Fig; ure 1.

Referring to the drawing in detail, it will be seen that the numeral 5 denotes an elon gated shoe which is secured longitudinally to the bottom of the boat 6 by means of screws 7 or in any other suitable manner. This shoe is provided with a longitudinally extending groove 8, the side walls of which converge toward each other to provide a restricted opening.

In the bottom of the groove 8 there is provided a longitudinally extending channel 9. At one end of the channel there is a pin 10. The numeral 11 denotes the fin which may be of any suitable size and shape and which is formed on its upper edge with a longitudinally extending rib 12 to slidably engage in the groove 8 and said rib has a relatively narrow strip 14 to slide in the channel 9 and one end of this strip abuts the pin 10 to limit the movement of the fin in one direction so that the same will not become detached in the water when the boat is in use.

Obviously the fin may be easily detached by slidingthe same away from the pin 10.

This pin 10 may vary in size but in actual practice it has been found desirable to construct the same approximately three thirty seconds of an inch of sufiicient strength to lock the fin. in place but of proper strength so that in the event the fin should come in c L t with a rock when the boat is travel ling in the'water that the pin will break or cut oil and release the fin without doing damage to the boat.

ihe fin 11 may be made of aluminum, bronze, or other metal and material and may be or different sizes and shape. The advantage of this invention is in the case of removing the fin for transportation of the boat or for hauling the boat on to a wharf or beach or otherwise. The usual fins 011 the market at the present time require them to be re moved by the release of screws or bolts. Every time that one of the undetachable fins is removed, screw holes or bolt holes are worn and enlarged making it necessary to change the position of the fin on the boat.

The present fin is designed primarily to be used on outboard motor boats, socalled. The primary object oi the fin is to provide a turning pivot although it also serves to hold the boat on its course and steady it.

It is thought that the construction, operation, utility and advantages oi? this invention will now be quite apparent to those skilled in this art withouta more detailed descrip tion thereof.

The present en'ibodiment oi; the invention has been disclosed in detail merely by way of example since in actual practice it attains the features of advantage enumerated as desirable in the statement of the invention and the above description.

It will be apparent that changes in the dotails of construction, and in the combination and arrangement of parts may be resorted to without departing from the spirit or scope of the invention or sacrificing any of its advantages.

Having thus described my invention, what I claim as new is:

1. In combination, a boat, a fin, quick detachable means for mounting the fin on the boat, said means comprising a slidable structure having a breakable pin limiting the movement of the fin in one direction.

2. In combination, a boat, a shoe rigidly secured to said boat, a groove in the shoe, a.

' fin, a rib on the fin slidable in the groove, said groove being formed With a, channel, an eX- tension on the rib in the channel.

3. In combination, a shoe, a groove in the shoe, a fin, a rib on the fin slidable in the groove, sait groove being formed with a channel an extension on the rib in the chan nel, av breakable pin in the channel to be engaged by the extension to limit the movement of the fin in one direction.

In testimony whereof 1 aiiiz: my signature.

WILLIAM s. DUPUIS. 

